Winter/Spring Flood Potential Outlook For Northern And Eastern Maine - 01/05/2023

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WINTER/SPRING FLOOD POTENTIAL OUTLOOK

NATIONAL WEATHER SERVICE CARIBOU ME

824 AM EST THU JAN 5 2023

...SPRING FLOOD POTENTIAL OUTLOOK FOR NORTHERN...CENTRAL...AND 

DOWNEAST MAINE...

THIS IS THE FIRST WINTER/SPRING FLOOD POTENTIAL OUTLOOK FOR 2023,

ISSUED BY THE NATIONAL WEATHER SERVICE IN CARIBOU, MAINE. THIS 

OUTLOOK IS FOR NORTHERN, CENTRAL, AND DOWNEAST MAINE FOR THE TWO- 

WEEK PERIOD OF JANUARY 5TH TO JANUARY 19TH, 2023. 

THE POTENTIAL FOR OPEN WATER FLOODING OVER THE NEXT TWO WEEKS IS 

NORMAL. THE POTENTIAL FOR ICE JAM FLOODING IS ABOVE NORMAL ACROSS 

THE NORTHERN BASINS. 

...CLIMATOLOGICAL GUIDANCE...

DECEMBER 2022 WAS SIGNIFICANTLY WARMER THAN AVERAGE WITH AT TO 

ABOVE AVERAGE TOTAL PRECIPITATION AND BELOW NORMAL SNOWFALL. THE 

REGION AS A WHOLE AVERAGED ABOUT 5.0 TO 6.5 DEGREES ABOVE THE 

1991-2020 CLIMATE NORMS. CARIBOU MONTHLY AVERAGE TEMPERATURE FOR 

DECEMBER 2022 WAS 26.4F WHICH WAS 3RD WARMEST ON RECORD WITH 

RECORDS DATING BACK TO 1939. IN HOULTON, THE AVERAGE TEMPERATURE 

WAS 27.5F WHICH WAS ALSO 3RD WARMEST ON RECORD WITH THEIR RECORDS 

DATING BACK TO 1948. MILLINOCKET, FEATURED AN AVERAGE MONTHLY 

TEMPERATURE OF 28.5F WHICH WAS THE 4TH WARMEST ON RECORD WITH 

RECORDS DATING BACK TO 1902. LASTLY, BANGOR’S DECEMBER 2022 

AVERAGE MONTHLY TEMPERATURE WAS 30.9F WHICH WAS ALSO 4TH WARMEST 

ON RECORD WITH RECORDS DATING BACK TO 1925. REPEATED WARM SPELLS 

WAS THE OVERALL THEME OF THE MONTH BROKEN ONLY BY RELATIVELY SHORT

PERIODS OF NEAR TO SOMEWHAT BELOW AVERAGE TEMPERATURES. NO 

EXTREMELY WARM DAYS OCCURRED, BUT NORTHERN LOCATIONS HAD SOME DAYS

WHERE HIGH TEMPS REACHED INTO THE 40S WITH CENTRAL AND DOWNEAST 

LOCATIONS OCCASIONALLY REACHING HIGHS INTO THE LOWER TO MID 50S, 

INCLUDING RECORD HIGH TEMPS ON THE LAST TWO DAYS OF THE MONTH. 

THERE WERE FEW ARCTIC AIR MASSES THAT ENTERED THE REGION WITH 

LITTLE ZERO AND SUB-ZERO LOW TEMPERATURES THIS MONTH. IN FACT, THE

LOW MONTHLY TEMPERATURE OF ZERO AT CARIBOU RECORDED ON THE 28TH 

WAS THE 4TH LATEST FIRST ZERO OCCURRENCE THERE.

TOTAL PRECIPITATION FOR THE MONTH RANGED FROM ABOUT 95 TO 125 

PERCENT OF AVERAGE ACROSS THE REGION WITH THE MAJORITY OF IT 

FALLING AS RAINFALL EVEN ACROSS THE NORTH. SIGNIFICANT RAINFALL 

EVENTS ON THE 3RD AND 7TH COMPLETELY LIQUIDATED EARLY SNOWPACKS 

FROM NOVEMBER OVER THIS PORTION OF THE REGION. ANOTHER HEAVY 

RAINFALL EVENT ON THE 23RD RESULTED IN MINOR FLOODING OVER 

SOUTHWEST PORTIONS OF THE EVENT FALLING AFTER AND MELTING MUCH OF 

THE HEAVY SNOWFALL LESS THAN A WEEK PRIOR.

SNOWFALL ACROSS THE REGION WAS RELATIVELY LIGHT, ONLY 50 TO 75 

PERCENT OF AVERAGE DUE TO FEW STORM SYSTEMS THIS MONTH TAKING A 

FAVORABLE TRACK FOR SNOWFALL. BY FAR AND AWAY, THE MOST IMPORTANT 

AND LONG DURATION EVENT BEGAN LATE ON THE 16TH OVER THE SOUTHWEST 

AND FINISHED LATE ON THE 19TH OVER THE NORTHEAST. INLAND FROM THE 

COAST OVER THE SOUTH AND WEST, THIS EVENT FEATURED HEAVY SNOW 

BANDING RESULTING IN SNOW TOTALS UPWARDS TO 20 INCHES OVER SOME 

CENTRAL AND WESTERN LOCATIONS AND ENDED ON THE 18TH. COASTAL 

DOWNEAST LOCATIONS HAD MUCH REDUCED SNOWFALL DUE TO MIXING OR EVEN

PERIODS OF ALL RAIN DURING THIS EVENT. OVER THE NORTHEAST, THE 

EVENT BEGAN ON THE AFTERNOON OF THE 17TH AND CONTINUED INTO THE 

EVENING OF THE 19TH WITH LIGHT STEADY SNOWFALL THAT STILL MANAGED 

TO ACCUMULATE OVER A FOOT AT MOST LOCATIONS. BLOCKING OVER 

NORTHEAST CANADA, WHICH WAS SLOWLY BREAKING DOWN, WAS THE REASON 

FOR THE SLOW NORTHEAST PROGRESSION OF THIS STORM. LOOKING 

AHEAD...THERE ARE CURRENTLY NO INDICATIONS THAT MAJOR ARCTIC AIR 

INTRUSIONS WILL OCCUR IN NEW ENGLAND OVER THE NEXT 10 DAYS OR SO. 

THE NORTH ATLANTIC OSCILLATION (NAO) INDEX IS FORECAST TO REMAIN 

POSITIVE RIGHT INTO THE MIDDLE OF JANUARY. WITH A POSITIVE NAO 

INDEX...THE JET STREAM REMAINS FAIRLY ZONAL WITH FAST MOVING 

WEATHER SYSTEMS RIPPLING ACROSS THE COUNTRY. MOST OF THE ARCTIC 

AIR REMAINS IN CANADA AND IS SHUNTED EASTWARD RATHER THAN HEADING 

SOUTHWARD INTO THE UNITED STATES. THE ONLY EXCEPTION TO THIS IS 

ACROSS NORTHERN MAINE WE CAN BE CLIPPED SEVERAL TIMES BY A BIT OF 

THIS ARCTIC AIR. LATEST LONG RANGE OPERATIONAL RUNS ARE BEGINNING 

TO SUGGEST THIS, HOWEVER TYPICAL WITH LONG RANGE GUIDANCE SO MANY 

THINGS CAN CHANGE UPSTREAM IMPACTING THE RESULTS. THE PACIFIC 

NORTH AMERICA (PNA) PATTERN IS FORECAST TO REMAIN WEAKLY POSITIVE.

A POSITIVE PNA FAVORS AN UPPER LEVEL TROUGH OVER THE EASTERN 

UNITED STATES BUT WITH A WEAKLY POSITIVE PNA...OFTEN THE TROUGHS 

ARE BROAD AND DO NOT SUPPORT RAPID EAST COAST STORM DEVELOPMENT. 

HERE IN EASTERN MAINE WE CAN SEE LAST MINUTE RAPID DEVELOPMENT 

OVER THE EASTERN GULF OF MAINE OR BAY OF FUNDY WHICH CAN PRODUCE 

SNOWFALL FOR OUR AREA BUT AT THIS TIME NOTHING IS EXPECTED.

THE CLIMATE PREDICTION CENTER`S OUTLOOK FOR THE MONTH OF JANUARY 

2023 IS CALLING FOR SLIGHTLY INCREASED ODDS OF ABOVE AVERAGE 

TEMPERATURE AND EQUAL ODDS OF BELOW, NEAR, OR ABOVE AVERAGE 

PRECIPITATION FOR OUR REGION. NORMAL JANUARY TEMPS FOR THE 

1991-2020 PERIOD FOR NORTHERN (DOWNEAST) MAINE ARE LOWS OF ZERO TO

5 ABOVE (5 TO 10 ABOVE) AND HIGHS OF LOWER 20S (UPPER 20S TO 

LOWER 30S). NORMAL JANUARY TOTAL PRECIPITATION FOR THE ENTIRE 

REGION IS AROUND 3.00 INCHES WITH NORMAL SNOWFALL RANGING FROM 15 

TO 20 INCHES OVER DOWNEAST AREAS UPWARDS TO 25 TO 30 INCHES ACROSS

FAR NORTHERN AREAS.

...OBSERVED SNOW DEPTH AND WATER EQUIVALENTS...

THE MAINE COOPERATIVE SNOW SURVEY JUST BEGAN THIS WEEK SHOWING A 

RATHER DISMAL SNOWPACK ACROSS EASTERN & NORTHERN MAINE. DUE TO THE

WARM END OF DECEMBER 2022 COMBINED WITH SEVERAL RAIN EVENTS WE 

ENTERED 2023 WITH A WELL BELOW NORMAL SNOWPACK THAT IS MAINLY 

CONFINED TO NORTHERN MAINE INCLUDING THE MOOSEHEAD REGION TO 

BAXTER AREA, NORTHERN WASHINGTON COUNTY AND THE CROWN. GREATER 

BANGOR AREA TO DOWNEAST COAST HAVE NO SNOWPACK EXCEPT WHAT IS 

FALLING THIS MORNING WHICH IS GENERALLY EXPECTED TO BE ONLY 1-2 

INCHES AND MAY LAST FOR A FEW DAYS. IN THE CENTRAL HIGHLANDS AND 

UPPER PENOBSCOT RIVER REGIONS SEE GENERALLY LESS THAN 6 INCHES OF 

SNOW DEPTH WHICH IS BELOW NORMAL FOR THIS TIME OF YEAR. IN 

ADDITION THE SNOW WATER EQUIVALENTS (SWE) ARE RUNNING BELOW NORMAL

GENERALLY LESS THAN 1.5 INCHES BUT ARE WATER LOADED SOME FROM 

RECENT RAINS. ACROSS THE NORTH WOODS INTO THE CROWN WE SEE SNOW 

DEPTHS GENERALLY 6 INCHES OR LESS BUT ACROSS HIGHER TERRAIN WEST 

AND NORTH OF CARIBOU & ASHLAND WE SEE SNOW DEPTHS 6-12 INCHES 

INCLUDING LOCATIONS OUT IN THE HEADWATERS OF THE ST. JOHN RIVER. 

SWE’S ACROSS THE NORTH ARE RUNNING 2-4 INCHES WHICH IS JUST 

SLIGHTLY BELOW NORMAL TO NEAR NORMAL BUT NOT BECAUSE OF THE SNOW 

DEPTH. THE HIGHER SWE’S ACROSS THE NORTH ARE DUE TO SIGNIFICANT 

WATER LOADING FROM THE SEVERAL RAIN EVENTS IN DECEMBER WHERE THE 

SNOWPACK ABSORBED AND CONDENSED.

...SOIL MOISTURE AND WATER SUPPLY CONDITIONS...

LEADING INTO DECEMBER WE HAD SEVERAL RAINS, FOLLOWED BY SEVERAL 

SMALL SNOW EVENTS THAT RESULTED IN A LOT OF DISCHARGED WATER WHEN 

THE WELL ABOVE NORMAL DECEMBER TEMPERATURES ARRIVED. THIS COMBINED

WITH SEVERAL RAIN EVENTS IN DECEMBER RESULTED IN VERY WET 

CONDITIONS WITH MELTING SNOWPACK. NEAR SURFACE SOIL MOISTURE 

ANOMALIES SHOW ALL OF EASTERN & NORTHERN MAINE HAVING ABOVE TO 

WELL ABOVE NORMAL SOIL MOISTURE. THE LATEST PALMER DROUGHT 

SEVERITY INDEX MAP FROM JANUARY 2, 2023 SHOWS THE DOWNEAST 

ABNORMALLY WET, GREATER BANGOR IS EXTREMELY WET AND MUCH OF THE 

REMAINING AREAS ARE SEVERELY TO EXTREMELY WET. THE PALMER INDEX 

LOOKS AT CONDITIONS OVER THE SPAN OF WEEKS TO MONTHS. 

TAKING A LOOK AT GROUNDWATER MONITORING WELLS ACROSS THE REGION 

COURTESY OF THE UNITED STATES GEOLOGICAL SURVEY (USGS), WE SEE 

MUCH OF THE GROUNDWATER LEVEL OBSERVING SITES ARE EXTREMELY HIGH 

FOR EARLY JANUARY. USGS MONITORING WELLS IN CLAYTON LAKE, FORT 

KENT, CALAIS AND KENDUSKEAG WERE ALL REPORTING RECORD HIGH JANUARY

LEVELS AS OF JANUARY 3, 2022. RECORDS FOR THESE WELLS GO BACK AS 

FAR AS 44 YEARS AS IS WITH THE FORT KENT SITE. 

LASTLY, GIVEN THE SIGNIFICANT RUNOFF FROM RAINFALL AND SNOWMELT 

WE ARE LOOKING AT RIVER STORAGES. WE FOCUS ON THE OBSERVATIONS WE 

GET FOR THE PENOBSCOT RIVER BASIN. THE PENOBSCOT TOTAL STORAGE AS 

OF JANUARY 2, 2023 WAS 75.5% FULL WHICH IS 34.2% ABOVE THE LONG 

TERM AVERAGE. 

...RIVER AND ICE CONDITIONS...

AS OF JANUARY 5TH EVERY RIVER, STREAM AND CREEK WITH USGS GAGES 

IN EASTERN & NORTHERN MAINE ARE REPORTING GREATER THAN 90TH 

PERCENTILE DAILY DISCHARGE VALUES. THIS MEANS EVERY MEASURED 

WATERWAY IS RUNNING MUCH ABOVE NORMAL. SEVERAL SITES INCLUDING THE

ST. FRANCIS RIVER, ST. JOHN RIVER, MEDUXENKEAG RIVER, EAST BRANCH

OF PENOBSCOT, PENOBSCOT RIVER, PISCATAQUIS RIVER AND KINGSBURY 

STREAM ARE RUNNING AT ALL-TIME HIGH DAILY DISCHARGE FOR THIS DAY. 

OVERALL, THIS MEANS WE HAVE WAY ABOVE NORMAL WATER IN THE RIVERS 

FOR JANUARY. 

INITIALLY WE DEVELOPED ICE ON THE RIVERS DURING THE MONTH OF 

DECEMBER MAINLY ACROSS THE NORTHERN RIVERS AND UPPER REACHES OF 

THE PENOBSCOT. SEVERAL RAINSTORMS AND MELTING SNOW OVER THE PAST 

FEW WEEKS ALLOWED FOR SIGNIFICANT SHIFTING AND BREAK UP OF THE ICE

THAT DEVELOPED. FRAZIL ICE COMPACTED AND THICKENED CREATING SHEET

ICE 3-6 INCHES THICK WITH ISOLATED THICKER ICE. THIS SHIFTED AND 

MOVED AROUND RESULTING IN SIGNIFICANT JUMBLED ICE. THIS WAS 

EVIDENT ON THE PENOBSCOT RIVER ABOVE THE HOWLAND DAM WHICH 

RESULTED IN ICE JAM FLOODING ON DECEMBER 28, 2022. EMERGENCY 

MANAGEMENT AND TOWN OFFICIALS REPORTED THAT EXCESSIVE RUNOFF ON 

MERRILL BROOK & GORDON BROOK ALONG WITH AN ICE JAM APPROXIMATELY 

2-3 MILES LONG ABOVE THE HOWLAND DAM CUT OFF SEVERAL RESIDENTS ON 

GARDNER LANE IN HOWLAND AND THREATENED MATTAMISCONTIS ROAD. WATER 

LEVELS RECEDED BUT THE ICE REMAINED AS OF JANUARY 1, 2023. 

AROUND THE START OF THE NEW YEAR A LARGE PORTION OF JUMBLE ICE 

ABOVE THE CARIBOU DAM DISCHARGED OVER THE DAM AND TRAVELED 

DOWNSTREAM INTO FORT FAIRFIELD COLLIDING WITH AN EXISTING JUMBLE 

JAM THAT EXTENDED 4-5MI UPSTREAM FROM THE NEW BRUNSWICK BORDER. 

THIS RESULTED IN WATER RISES THAT BEGAN TO FLOOD THE GRIMES ROAD /

NORTH CARIBOU ROAD AT THE FORT FAIRFIELD AND CARIBOU TOWNLINE 

WHICH WAS CLOSED. IN ADDITION WE SAW FLOODING OF THE LOW-LYING 

FARM FIELDS ALONG ROUTE 161 BETWEEN FORT FAIRFIELD AND CARIBOU. 

THIS ICE JAM GREW TO BETWEEN 9 AND 12 MILES STRETCHING FROM NEAR 

TINKER DAM IN NEW BRUNSWICK TO RIVER ROAD IN CARIBOU. WELL ABOVE 

NORMAL DISCHARGE CONTINUES TO FLOW DOWN THE LITTLE MADAWASKA RIVER

WHICH ADDS MORE WATER INTO THE AROOSTOOK RIVER. THANKFULLY BY 

JANUARY 4TH THE WATER RECEDED AND THE GRIMES ROAD / NORTH CARIBOU 

ROAD WAS REOPENED. THE ICE JAM REMAINS IN PLACE. 

LASTLY, WE HAVE JUMBLED ICE STRETCHING FROM MADAWASKA DOWNSTREAM 

TO HAMLIN. THERE HAS BEEN SOME ICE SHIFTING THAT HAS TURNED INTO 

AN ICE JAM BUT THANKFULLY NO FLOODING IN THE HAMLIN AREA OR 

UPSTREAM REPORTED. PICTURES VIA SOCIAL MEDIA INDICATE IT'S A JAM 

ABOVE GRAND FALLS STRETCHING BACK SEVERAL MILES ON THE ST. JOHN 

TOWARDS VAN BUREN. USING THE PHOTOGRAPHS THE ICE THICKNESS IS 

ESTIMATED TO BE 3-6 INCHES. 

ELSEWHERE, NO SIGNIFICANT ICING OTHER THAN FRAZIL ICE AND THIN 

BANK ICE IS PRESENT ON PISCATAQUIS, MATTAWAMKEAG AND OTHER 

STRETCHES OF THE PENOBSCOT AND DOWNEAST RIVERS AND STREAMS. 

...IN CONCLUSION...

THE POTENTIAL FOR FLOODING DUE TO ICE JAMS IS ABOVE NORMAL ACROSS

NORTHERN MAINE. ICE JAMS REMAIN IN PLACE ALONG PORTIONS OF THE 

AROOSTOOK, ST. JOHN AND PENOBSCOT RIVERS ALTHOUGH FLOODING HAS AT 

LEAST TEMPORARILY SUBSIDED. WITH HIGH OR RECORD HIGH FLOWS 

CURRENTLY OCCURRING THERE IS A RISK FOR MORE FLOODING IF THE JAMS 

SHIFT. THE RIVERS AND STREAMS WILL ALSO LIKELY BEGIN TO RE-FREEZE 

AT HIGH STAGES WHICH MAY INCREASE THE LIKELIHOOD FOR FREEZE-UP 

JAMS WHEN COLD AIR RETURNS. 

FOR ALL THESE REASONS...THE POTENTIAL FOR FLOODING DUE TO ICE 

JAMS REMAINS ELEVATED ACROSS NORTHERN MAINE.

THE NEXT WINTER/SPRING FLOOD OUTLOOK WILL BE ISSUED ON THURSDAY, 

JANUARY 19TH. 

$$

SINKO